Numb protein (Wakamatsu et al., Neuron, 23, 71-81, 1999) is known to inhibit the signaling cascade of Notch protein which is required for the self-renewing activity of mammalian central neural stem cells (Ohtsuka et al., EMBO J., 18, 2196-2207, 1999; Nakamura et al., J. Neurosci., 20, 283-293, 2000).
Further, a Notch-protein-mediated signaling system takes part in the self-renewal, survival and/or the status of neural stem cells (Artavanis-Tsakanos et al., Science, 268, 770-776, 1999).